Thread-controlling mechanism for sewing machines



Jan. 8 1924.

G. S. GATCHELL THREAD CONTROLLING MECHANISM FOR SEWING MACHINES Filed Feb. 5. 1920 a Sheeis-Sheet 1 INVENTOR WITNESSES: M firkhd,

ATTORNEY 1924. 1,479,907 G. S. GATCHELL THREAD CONTROLLING MECHANISM FOR SEWING MACHINES Filed Feb. 5, 1920 3 Sheets-Sheet 2 7 Jan. '8

' INVENTOR WITNESSES:

Jan. 8 1924.

G. s. GATCHELL THREAD CONTROLLING MECHANISM FOR SEWING MACHINES 1920 3 Sheets-Sheet 5 Filed Feb. 3

INVENTOR w S E S S E N H W TTORNEY Patented Jan. 8, 1924.

UNITED STATES 1,479,907 PATENT OFFICE.

enonen s. GATCHELL, or ROSEQLE PARK, NEW JERSEY, ASSIGNOR T mm smann MANUFACTURING comrAia'z, or ELIZABETH, NEW JERSEY, A CORPORATIONOF NEW JERSEY.

THREAD-CONTROLLING mncnANIsm 'ron snwmo MACHINES.

App cation filed February a, 1920. Serial No. asaoov.

To aw'uihom it my concern:

Be it known that I, Gnome S. GATOHELL, a citizen of the United States, residing at Roselle Park, in the county of Union and State of New Jersey, have invented certain new and useful Improvements in Thread- Controlling Mechanism for Sewing Machines, of which the followin is a specification, reference being had t erein to the accompanying drawings.

This invention relates to thread-controlling mechanism for sewing machines, more particularly of the multiple-needle singlelooper type. In prior machines it has been customary to provide intermittently acting tension devices for locking the needlethreads on the supply side of the take-up means during the greater portion of the stitch-forming cycle, the needle-threads being released only durin the brief period of the cycle when thread is being normally pulled from the supply. When the needle-, threads are locked during the major portion of the stitch-forming cycle, an abnormal demand for needle thread by the stitchforming instrumentalities at any time during the cycle, except during the brief period when the tensions are open, will unduly strain or break the needle-thread. An abnormal demand for needle-thread may result from various causes, such as sewing over a previously formed cross-seam, an occasional malformed stitch, etc.

The resent invention has for an object to provide a thread-controllin mechanism, adapted more particularly or multipleneedle single-looper machines, which will operate at high speed to properly tighten the stitches, and in which the tendency toward thread-breakage is reduced to a minimum.

A further object of the invention is to provide the improved thread-controlling mechanism in such form as to retain the advantages of ready detachability inherent in my prior thread-controlling mechanism disclosed in my Patent No, 1,361,247fof December 7 1920.

A further object of the invention is to provide a simple and eilicient thread-controlling and intermittent tension mechanism, of general application .to sewing machines.

The ob'ects of the invention are attained by providing a, take-up cam with a lateral extension operating through suitable connections to intermittently actuate a tension (.IBVICEL. In the particular embodiment of the invention to be described, a plurality of simple cam-and-lever devices are utilized for operating their respective tension devices successively in combination with the threadcontrolling or take-up devices which operate to successively tighten the needle-thread loops as they are shed from the looper. The timing of each thread-lock or tension-device 1s such that it is closed'upon its respective needle-thread only during the brief period of the cycle when the corresponding needleloop is being tightened or drawn up to the work, and is open during the ma or portion of the stitch-forming cycle. Thus, in the event of an abnormal demand upon the needle-thread by the stitch-formin instrumentalities, thread may be drawn Irom the supply without being subjected to adnormal strain. The invention further comprises certain details of construction hereinafter referred to and particularly pointed out in the appended claims.

In the accompanying drawings, Fig. 1 is a side elevation, partly in section, of a machine embodying the invention. Fig. 2 is a top plan view of the thread-controlling mechanism and its supporting frame detached from themachine. Fig. 3 is a section on the line 3-3, of Fig. 2. Fig. 4.- is a perspective-view of a cam'and lever element of the tension-actuating mechanism. Fig. 5 is a perspective'view of the needles an looper at the point of the cycle when the first needle-loop shed by the looper is heing tightened. Fig. 6 is a diagrammatic view of the several thread-controlling and tension operating cams shown in Fig. 2, and Fig. 7 is a perspective view of one of the thread-guide and nipper-lever unit assemblies constituting a part of the thread-controlling mechanism.

For the purposes of the present disclosure I have chosen to embody the invention in a machine such as described in m said 00- pending application. The mac ine comprises a frame formed with the standard 1 carrying the horizontal work-supporting and bracket-arms 2 and 3, respectively, the latter terminating in the head 4 in which is journaled the reciprocating needle-bar 5 carrying the needles 6 having their eyes 6' arranged as usual at progressively higher elevations beginnin with the ri ht-hand needle, Fig. 5, whic handles the t read The needle-bar is operated in the usual man ner from the crank 7 on the main-shaft 8 by means of the pitman 9, needle rock-shaft 10' and link 11.

The needles coo rate as usual with the. looper 12, the nee es rising as theilooper advances and seizes the needle-loops and descending as the looper retracts and sheds the needle-loops. The looper 12 is mounted at the forward end of the rocking and sliding looper-shaft 13 which extends within and longitudinally of the work-supporting arm 2 and is operated in any suitable manner from the main-shaft 8; the mechanism disclosed in my Patent No. 1,410,057 of March 21, 1922, being preferred.

The machine further comprises the fulling and main feed-dogs 14 and 15, respectively, which act infopposition to the vertically movable presser-foot 16, and the usual tension devices 17 for lightly restraining or steadying the various sewing threads.

In the present machine the needle-threads t, t t 15* are differentially controlled by means of the respective thread-controlling cams 0', 0 0 and 0*,eachof' which preferably comprises two similar spaced disks 0? formed integral with a common hub h which projects laterally at one side of said disks, as shown in Figs. 2 and 4. These cams are mounted on the cam-shaft 18 which is journaled in the bearings 19 of a thread-controller frame 20 which is detachably mounted on top of the bracket-arm 3 of the sewing machine frame by means of. screws 21. The shaft 18 is driven by means of the bevel gear connection 22 with the inclined shaft 23 inclosed within the shaft casing 24. The lower end of the shaft 23 is connected to the main-shaft 8 by means of the bevel pinion 25 meshing with the bevel gear 26 which is rigidly secured to and is concentric with the spur gear 27 the latter meshing with the driving gear 28 on the main-shaft 8. The ratio of gearing is such that the shaft 18 makes one revolution per revolution of the main-shaft.

Rising from the thread-controller frame 20 are two standards 29. to each of which are pivoted the shanks of two similar forkshaped thread-guides 30, the tines of each fork being disposed at opposite sides of a corresponding one of the thread-cams c'--c and apertured at 31 to guide the thread across the active peripheral portion of the respective thread-cams. Threaded into the shank of each thread-guiding fork 30 is an adjusting screw 32 which determines the po sition or height of the threaded-eyes 31. A spring 33 presses against the inclined rear end of the shank of each fork and yieldingly maintains the screw 32 in contact with a top-surfaoeportion 34 of the standard 29.

acraeov One of the tines of each fork 30 is extended sponding stripper-plate 36, the upper extremity of which is slotted at 37 to guide the thread and to cause the res ective threadcam to deflect the thread radially along said slot, thereby overcoming the tendency of the cam to carry the thread around with it. The shanks 38 of. the stripper-plates 36 are clamped in Suitable slots in the frame 20..

Cooperating with the thread-cams area series of intermittent tension devices or thread nippers r, w r and 1' one for each needle-thread. As these tension devices or nippers are all alike, a description of one will sufiice. Referring to Fig. 3 it will be seen that each tension-device or threadnipper comprises a sleeve 39 which is fixed in a socket in an upward extension 40 of the thread-controller frame 20. Theupper end of the sleeve 39 is slightly enlarged to form a circular head or stationary thread nipper disk 39. Fixed Within'the sleeve 39 is the push pin 41 to the upper end of which is fixed the head or thread-nipping disk 41' which nips and locks the thread against the top of the sleeve 39, under the influence of the relatively strong coiled spring 42. The

spring 42- surrounds the pin 41 and reacts against a shoulder within the sleeve 39 and a spaced shoulder within the smaller sleeve 43 telescopically received within the sleeve 39 and sustained by a cross-pin 44 extending diametrically through the pin 41.

Referring to Figs. 2 and 6, it will be seen that the hubs h of the cams c-0 are cylindrical throughout the major portions of their respective circumferences but are formed with the respective flats f'f, whereby said hubs constitute tension-controlling cams which operate through the parallel levers 45 to lift the pins 41 against the expansive forces of the springs 42 and release the needle-threads. Each ofthe levers 45 carries atits forward end a follower roll 46 which bears upwardly against its respective tension-controlling cam. These levers are pivoted to the standards 29 by means of the horizontally disposed screws 47 and, at. their rearward ends, are formed with angular extensions terminating beneath the pins 41 of the respective tension devices r'r*. It will be evident that when the cylindrical portion of one of the tensioncontrolling cams is in contact with the roll 46, the corresponding tension device will be held open and when the center of the corresponding flat reaches the roll 46 the upward pressure of the lever 45 upon the pin 41 will be relieved and the spring 42 permitted to and successively release their Referring to Fig. 6, it will be observed that the flats f;* are timed to act successively so that the tensions will successively lock respective needle-threads.

The needle-threads t't extend forwardly from the respective thread-eyes 31 in the thread-guiding forks 30 and pass through the eyelets 50 in the thread-guiding bracket 51 which is carried by the needle-bar 5. From this point the needle-threads lead downwardly to the needles.

Qpemtion.

The thread-controlling cams carried by the shaft 18 are shaped substantially as as shown in Fig. 6. Starting with the needles at their highest point, the point s, Fig. 6, of the cams 0-c is' coincldent with the thread-guiding slots 37 in the stripperplate 36 or, in other words. is even with the thread-eyes 31. At this time, the nlppers 1-'r are all open; the threads being lightly restrained or steadied, however, by the usual tensions 17. As the needles descend the looper retracts, and the outwardly inclined portions of the cams following the point 8 positively take up or absorb the slack thread given up by the descending thread-guldmg bracket 51 on the needle-bar, thereby preventing the formation of slack-thread below the needle-eyes and maintaining the previous needle-loops snugly about the looper-blade.

As the eye of the needle for the. thread t enters the work, the peak a of the cam 0 passes the thread-guiding slot 37 and the inward inclination of the cam 0 following the peak u gives up the thread required by the eye of the needle as it doubles its thread t below the work. Similarly, at successively later stages, the peaks u a and u of the cams c', c and 0', pass the thread-guiding slot 37, as the eyes of the corresponding needles descend below the work, and the inward inclines following said peaks give up the thread required by the respective needleeyes as they double their threads below the work.

As the point 22 reaches the thread-guiding slot 37, the previously formed needle-loop of the thread 2? is shed from the looper, the needles 6 continui on their down stroke at this time, as shown y the arrow, Fig. 5. The center of the fiat f now moves into a position over the roll 46 of its respective tension-controlling lever 45 and permits the tension-device r to close upon and lock the thread t While the thread 25 is looked, the outward inclination following the point e and leading to the peak 10 acts to positively tighten said loop or draw it up to the under side of the .work. Similarly, as the points '0 v and '0 of the take-ups successively pass the thread-guiding slot 37, the previously formed needle-loops of the respective threads i t and t are successively shed by the retracting looper on the down stroke of the needles and the respective nippers r, r and 1" are successively closed preparatory to the successive tightening of the needle-loops by the incline leading to the respective peaks w, w and w of the take-up cams. When the pointel' reaches the slot 37, the center of the fiat fhas passed its respective follower roll 46 sufliciently to cause depression of said roll and a consequent release of the thread t. Similarly, at successively later stages the centers of the flats i f and f pass their respective follower rolls and cause the successive opening of the tensions 1-, r and 7" after the respective needle-loops are tightened.

The remaining portions of the cams c'c act to control the needle-threads in ,the manner described in my copending applications, but with the exception that the tensions 1"-1'* are held open to permit the needlethreads to be drawn from the supply through the light tensions 17 to meet any demand for thread by the stitch-forming instrumentalities at all periods of the stitchforming cycle except during the brief perlods above mentioned when the needleoops shed by the looper are being drawn up to the under side of the work.

While I have shown and described the invention as embodied in a multiple-needle single-looper machine, it is, in certain of its aspects, applicable to sewing machines of various other types. The invention therefore is not to be considered as limited to a multiple-needle single-looper machine except in so far as such limitations may be set forth in the appended claims.

Having thus set forth the nature of the invention, what I claim herein is 1. In a sewing machine, the combination with a pluralty of needles having their eyes arranged at difi'erent elevations, of a plurality of thread-tension devices one for each needle-thread, and actuating means operating successively close said devices on their respective threads during the down-stroke of said needle.

2. In a sewing machine, in combinaton, a plurality of needles, needle-thread takeup means, a plurality of thread-tension devices on the thread-supply side. of said takeup means. and actuating means operating to successively close said devices on their respective threads during the down-stroke of said needles.

3. In a sewing machine, in combination, a plurality of reciprocating needles, a looper cooperating therewith to form stitches, takeup means successively tightening the needleloops as they are shed by the looper, and means for successively nipping the needlethreads while the needle loops are being tightened. v

4. In a sewing machine, in combination, a plurality of reciprocating needles, alooper, means for successively tightening the needleloops as they are shed by the loopcr, a plurality of needle-thread tensions, and means operating'to actuate said tensions successively to hold their respective needle-threads while the needle-loops are being tightened and release the needle-threads after the needle-loops have been drawn up.

5. Thread-controlling mechanism for sewing machines comprising, a threadgtension, a rotary take-up cam-disk having a laterally extending hub forming a tension-controlling cam, and a follower lever pivoted on an axis parallel to the axis of the take-up and serving to connect said cam and tension device.

6. Thread-controlling mechanism for multi-needle sewing machines comprising, a thread-controller frame adapted to be deacao? alongside said shaft, and a plurality of par- I allel levers connecting each tension-controlling cam with its respective tension device.

In testimony whereof,-l[ have signed my name to this specification. v

stones s. GATOHELL.

his, 

